diffing between different releases (#131)

- Add diff release subcommand to compare different releases
- Update subcommands usage in README
 - (Extra!) Adds go report card badge and license badge to README

Resolves #130

Author: codenio

README.md

@@ -1,4 +1,6 @@
 # Helm Diff Plugin
+[![Go Report Card](https://goreportcard.com/badge/github.com/databus23/helm-diff)](https://goreportcard.com/report/github.com/databus23/helm-diff)
+[![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://github.com/databus23/helm-diff/blob/master/LICENSE)
 
 This is a Helm plugin giving your a preview of what a `helm upgrade` would change.
 It basically generates a diff between the latest deployed version of a release
@@ -33,6 +35,7 @@ Usage:
   diff [command]
 
 Available Commands:
+  release     Shows diff between release's manifests
   revision    Shows diff between revision's manifests
   rollback    Show a diff explaining what a helm rollback could perform
   upgrade     Show a diff explaining what a helm upgrade would change.
@@ -89,6 +92,41 @@ Global Flags:
       --no-color   remove colors from the output
 ```
 
+### release:
+
+```
+$ helm diff release -h
+
+This command compares the manifests details of a different releases created from the same chart
+
+It can be used to compare the manifests of
+
+ - release1 with release2
+	$ helm diff release [flags] release1 release2
+   Example:
+	$ helm diff release my-prod my-stage
+
+Usage:
+  diff release [flags] RELEASE release1 [release2]
+
+Flags:
+  -C, --context int            output NUM lines of context around changes (default -1)
+  -h, --help                   help for release
+      --home string            location of your Helm config. Overrides $HELM_HOME (default "/home/aananth/.helm")
+      --include-tests          enable the diffing of the helm test hooks
+      --suppress stringArray   allows suppression of the values listed in the diff output
+  -q, --suppress-secrets       suppress secrets in the output
+      --tls                    enable TLS for request
+      --tls-ca-cert string     path to TLS CA certificate file (default "$HELM_HOME/ca.pem")
+      --tls-cert string        path to TLS certificate file (default "$HELM_HOME/cert.pem")
+      --tls-hostname string    the server name used to verify the hostname on the returned certificates from the server
+      --tls-key string         path to TLS key file (default "$HELM_HOME/key.pem")
+      --tls-verify             enable TLS for request and verify remote
+
+Global Flags:
+      --no-color   remove colors from the output
+```
+
 ### revision:
 
 ```

cmd/release.go

@@ -0,0 +1,111 @@
+package cmd
+
+import (
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"k8s.io/helm/pkg/helm"
+
+	"github.com/databus23/helm-diff/diff"
+	"github.com/databus23/helm-diff/manifest"
+)
+
+type release struct {
+	client           helm.Interface
+	detailedExitCode bool
+	suppressedKinds  []string
+	releases         []string
+	outputContext    int
+	includeTests     bool
+}
+
+const releaseCmdLongUsage = `
+This command compares the manifests details of a different releases created from the same chart
+
+It can be used to compare the manifests of
+
+ - release1 with release2
+	$ helm diff release [flags] release1 release2
+   Example:
+	$ helm diff release my-prod my-stage
+`
+
+func releaseCmd() *cobra.Command {
+	diff := release{}
+	releaseCmd := &cobra.Command{
+		Use:   "release [flags] RELEASE release1 [release2]",
+		Short: "Shows diff between release's manifests",
+		Long:  releaseCmdLongUsage,
+		PreRun: func(*cobra.Command, []string) {
+			expandTLSPaths()
+		},
+		RunE: func(cmd *cobra.Command, args []string) error {
+			// Suppress the command usage on error. See #77 for more info
+			cmd.SilenceUsage = true
+
+			if v, _ := cmd.Flags().GetBool("version"); v {
+				fmt.Println(Version)
+				return nil
+			}
+
+			switch {
+			case len(args) < 2:
+				return errors.New("Too few arguments to Command \"release\".\nMinimum 2 arguments required: release name-1, release name-2")
+			}
+
+			if q, _ := cmd.Flags().GetBool("suppress-secrets"); q {
+				diff.suppressedKinds = append(diff.suppressedKinds, "Secret")
+			}
+
+			diff.releases = args[0:]
+			if diff.client == nil {
+				diff.client = createHelmClient()
+			}
+			return diff.differentiate()
+		},
+	}
+
+	releaseCmd.Flags().BoolP("suppress-secrets", "q", false, "suppress secrets in the output")
+	releaseCmd.Flags().StringArrayVar(&diff.suppressedKinds, "suppress", []string{}, "allows suppression of the values listed in the diff output")
+	releaseCmd.Flags().IntVarP(&diff.outputContext, "context", "C", -1, "output NUM lines of context around changes")
+	releaseCmd.Flags().BoolVar(&diff.includeTests, "include-tests", false, "enable the diffing of the helm test hooks")
+	releaseCmd.SuggestionsMinimumDistance = 1
+
+	addCommonCmdOptions(releaseCmd.Flags())
+
+	return releaseCmd
+}
+
+func (d *release) differentiate() error {
+
+	releaseResponse1, err := d.client.ReleaseContent(d.releases[0])
+	if err != nil {
+		return prettyError(err)
+	}
+
+	releaseResponse2, err := d.client.ReleaseContent(d.releases[1])
+	if err != nil {
+		return prettyError(err)
+	}
+
+	if releaseResponse1.Release.Chart.Metadata.Name == releaseResponse2.Release.Chart.Metadata.Name {
+		seenAnyChanges := diff.DiffReleases(
+			manifest.ParseRelease(releaseResponse1.Release, d.includeTests),
+			manifest.ParseRelease(releaseResponse2.Release, d.includeTests),
+			d.suppressedKinds,
+			d.outputContext,
+			os.Stdout)
+
+		if d.detailedExitCode && seenAnyChanges {
+			return Error{
+				error: errors.New("identified at least one change, exiting with non-zero exit code (detailed-exitcode parameter enabled)"),
+				Code:  2,
+			}
+		}
+	} else {
+		fmt.Printf("Error : Incomparable Releases \n Unable to compare releases from two different charts \"%s\", \"%s\". \n try helm diff release --help to know more \n", releaseResponse1.Release.Chart.Metadata.Name, releaseResponse2.Release.Chart.Metadata.Name)
+	}
+	return nil
+}

cmd/root.go

@@ -56,6 +56,7 @@ func New() *cobra.Command {
 	cmd.AddCommand(
 		revisionCmd(),
 		rollbackCmd(),
+		releaseCmd(),
 	)
 	cmd.SetHelpCommand(&cobra.Command{}) // Disable the help command
 	return cmd

diff/diff.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"io"
 	"math"
+	"sort"
 	"strings"
 
 	"github.com/aryann/difflib"
@@ -51,6 +52,13 @@ func DiffManifests(oldIndex, newIndex map[string]*manifest.MappingResult, suppre
 	return seenAnyChanges
 }
 
+// DiffReleases reindex the content  based on the template names and pass it to DiffManifests
+func DiffReleases(oldIndex, newIndex map[string]*manifest.MappingResult, suppressedKinds []string, context int, to io.Writer) bool {
+	oldIndex = reIndexForRelease(oldIndex)
+	newIndex = reIndexForRelease(newIndex)
+	return DiffManifests(oldIndex, newIndex, suppressedKinds, context, to)
+}
+
 func diffMappingResults(oldContent *manifest.MappingResult, newContent *manifest.MappingResult) []difflib.DiffRecord {
 	return diffStrings(oldContent.Content, newContent.Content)
 }
@@ -137,3 +145,34 @@ func calculateDistances(diffs []difflib.DiffRecord) map[int]int {
 
 	return distances
 }
+
+// reIndexForRelease based on template names
+func reIndexForRelease(index map[string]*manifest.MappingResult) map[string]*manifest.MappingResult {
+
+	// sort the index to iterate map in the same order
+	var keys []string
+	for key := range index {
+		keys = append(keys, key)
+	}
+	sort.Strings(keys)
+
+	// holds number of object in a single file
+	count := make(map[string]int)
+
+	newIndex := make(map[string]*manifest.MappingResult)
+
+	for key := range keys {
+
+		str := strings.Replace(strings.Split(index[keys[key]].Content, "\n")[0], "# Source: ", "", 1)
+
+		if _, ok := newIndex[str]; ok {
+			count[str]++
+			str += fmt.Sprintf(" %d", count[str])
+			newIndex[str] = index[keys[key]]
+		} else {
+			newIndex[str] = index[keys[key]]
+			count[str]++
+		}
+	}
+	return newIndex
+}